Typhoid and paratyphoid (enteric fever) Flashcards
1
Q
typhoid is a bacterial infection due to
A
to a specific type of Salmonella that causes symptoms. Symptoms may vary from mild to severe, and usually begin 6 to 30 days after exposure. Often there is a gradual onset of a high fever over several days
2
Q
patient risk factors
A
- Recent travel to Asia (also Africa and S. America)
- Poor sanitation
- Young age
- Microbial resistance
3
Q
pathogen
A
Salmonella typhi and Salmonella paratyphi
4
Q
Salmonella typhi and Salmonella paratyphi
A
Enterobacteriaceae aerobic gram-negative bacillus
5
Q
virulence factors
A
- Low infectious dose
- Survives gastric acid
- Fimbriae adhere to epithelium over ileal lymphoid tissue (Peyers patches) RE system/ blood
- Reside within macrophages (liver/spleen/bone marrow)
6
Q
Patient symptoms
A
- Systemic disease (bacteraemia/sepsis)
- 7-14 day incubation period
- Fever
- Headache
- Abdominal pain
- Dry cough
- Rash
- Relative bradycardia
7
Q
mechanism of infection
A
- Faecal-oral from contaminated food/water
- Source is cases or carriers
8
Q
FBC results
A
- Moderate anaemia
- Lymphopenia
- Mild raised LFT (transaminase and bilibubin)
9
Q
culture
A
o Blood (+ve in 40-80%) o Faeces, bone marrow
10
Q
serology
A
not reliable
11
Q
Treatment
A
- IV ceftriaxone (cephalosporin) or azithromycin (macrolide) for 7-14 days
- Multi-drug resistant (inc. Penicillin’s)
- Fluroquinolones (e.g. cipro) may work- but increasing resistance
12
Q
Prevention
A
- Food and water hygiene precautions
- Typhoid vaccine
o High risk travel
13
Q
vaccine available
A
Capsular polysaccharide antigen or live attenuated
Moderate protective effect (50-75%)
14
Q
Outcome of infection
A
Complications
- Intestinal haemorrhage and perforation
- 10% mortality (untreated)
- Chronic carrier state 1-5%
- Paratyphoid is generally milder
